Training tomes bugging out

Well, I've recently encountered a bug where-as training tomes, when leveling up a companion, disappear once the companion is leveled up, and the experience is reset back to level he/she was at previously. Ex. 59-60, 2 tomes were used, and my El Toro leveled up, but it didn't give him the experience, and the tomes were wasted, and his level reset back to 59 when I leveled him up. I'm concerned about this bug, since at higher levels training tomes become more expensive, so I virtually wasted around 16,000 gold, due to this bug. I would appreciate if one of you guys told me about it, and if it's being noticed by others as well, so that moderators will know whether it is a big glitch, or just one that occurs every once in awhile.